Jeff and Deb wrote:
>
> I noticed, that when at idle, at operating temp, that loading on electrical
> accessories such as high beams, and/or front and rear fans, tends to make my
> idle cycle in a very sine wave like manner.  As soon as the lights are
> dimmed, or other electrical load is removed, it goes back to a very smooth
> idle.
>
> Does this sound like a familiar problem to anyone?  I could not find
> anything in the recent archives about it.
> Jeff Hartman
> Juneau, AK
> 86 Vanagon

I know this is an old thread but-

It sound like you are having trouble getting the available power put out
by the Alt to the loads that require it.

Causes:

- Too much demand.
- Drain or short somewhere.
- Poor contacts in the wire to chassis to battery Dept.

Possible Fixes:

- Reduce demand OR better yet increase output of Alt. (Buy greater amp output)
- Test amp draw between battery post and disconnected cable. Milli-amps
OK, alarm and or radio draw a trickle.
- Clean and recondition the ground straps, Hot side loom and battery
post cable ends.

This last can work seeming Miracles in old and not so old vehicles. The
trouble is oxidation and weathered cables add too much work for the
power at hand, cleaning the battery posts, the places the ground straps
connect, adding a wire from the Alt's CASE to chassis ground and/or the
eng. block, coating those newly cleaned contacts and post with
dielectric grease or at least a light coat of petroleum jelly, and
replacing the old battery cables with nice thick new ones will
're-energize' your charging and electrical system(s).

Don't forget all those brown wire grounds either, they can be found in
the strangest hiding places like up under the dashboard or in the rear
corners and what not.

Help the electrons get where they are going,
hth.

TBerk